June Lockhart Cause of Death: TV’s Beloved Mom from “Lassie” and “Lost in Space” Dies at 100

June Lockhart, the warmhearted television icon who embodied American motherhood in “Lassie” and the pioneering spirit in “Lost in Space,” has died at the age of 100. Her family said she passed away of natural causes on Thursday, October 23, 2025, at her home in Santa Monica, California.

A century-long life in front of the camera

Born June 25, 1925, in New York City to actors Gene and Kathleen Lockhart, she entered show business almost by inheritance. She appeared on stage and in films as a child—earning early notice in holiday classics—before building a versatile résumé across theater, movies, and, ultimately, the medium that made her a household name: television.

Lockhart won a Tony Award in 1948 early in her career, a sign of the range she would continue to display as television matured. But it was the small screen that turned her into a national touchstone, thanks to two indelible roles that spanned very different genres.

America’s mom—and a space-age matriarch

From 1958 to 1964, Lockhart portrayed Ruth Martin on “Lassie,” offering gentle authority and steady warmth in a series that defined family entertainment for a generation. She then leapt from farm to frontier, playing Maureen Robinson in “Lost in Space” (1965–1968). The shift showcased her adaptability: the same poise that reassured a fictional son and a collie also anchored a family marooned among the stars.

Her presence on-screen—calm, composed, and quietly commanding—helped normalize women as decision-makers and problem-solvers in prime-time homes across America. Even when the plots turned fantastical, Lockhart grounded them with sincerity.

Beyond the soundstage: curiosity and civic spirit

Friends and colleagues often described Lockhart as an avid reader and a tireless conversationalist, engaged with current events until the end of her life. Her long-standing interest in science and exploration connected naturally with her spacefaring TV persona; she maintained ties with space enthusiasts and celebrated technological milestones with genuine enthusiasm.

Milestones and accolades

• Tony Award (1948): Recognition for her early stage excellence.

• Two Primetime Emmy nominations: Acknowledging her television prominence during the medium’s formative decades.

• Cross-genre longevity: Film, stage, daytime and prime-time TV, plus a late-career cameo nodding to her “Lost in Space” legacy.

A legacy that outlived the credits

Lockhart’s hallmark was the way she made care feel active rather than passive. On “Lassie,” comfort came hand-in-hand with common sense; on “Lost in Space,” maternal instinct coexisted with adaptability and grit. Those portrayals helped set the template for generations of TV mothers and leaders—women whose empathy didn’t diminish their agency.

Her death closes a chapter from Hollywood’s golden-to-silver-age bridge: artists who began in studio-era films, conquered live and early taped television, and remained relevant long enough to wave at reunions in the streaming era. Few performers carried that span with as much grace.

Survivors, services, and remembrance

Lockhart is survived by family who were at her side in Santa Monica. A private service is expected, with public tributes to follow. Fans honoring her memory often reach for a simple image: a reassuring smile at a kitchen table, or a steady voice in a spaceship’s chaos—both equally, unmistakably June.

Cause of death, confirmed

For readers seeking the essential detail: June Lockhart died of natural causes. She was 100 years old, passing peacefully at home on October 23, 2025.

Her body of work remains easy to find—and worth revisiting. Whether you return to the black-and-white fields of a farm or the colorful corridors of a Jupiter-bound craft, the constant is Lockhart’s humane presence. It’s a legacy of kindness, intelligence, and steadiness that still feels modern, and that will continue to comfort audiences for years to come.